Ao Huaisheng, Zhu Weiduo, Liu Mengke, Zhang Wanqun, Hou Zhiguo, Wu Xiaojun, Zhu Yongchun, Qian Yitai
Hefei National Laboratory for Physical Science at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, P. R. China.
Small Methods. 2021 Jul;5(7):e2100418. doi: 10.1002/smtd.202100418. Epub 2021 May 24.
Aqueous sodium-zinc hybrid ion batteries are attracting extensive attention due to high energy density, low cost, and environmental friendliness. Unfortunately, there are still some drawbacks associated with the low voltage and cycle performance degradation that limit their practical application. Here, a concentrated aqueous electrolyte with solvation-modulated Zn is reported that reduces the hydrogen evolution reaction on the surface of Zn metal, avoiding the generation of ZnO and uneven deposition. Accordingly, the Zn anode exhibits 1600 h Zn plating/stripping and ≈99.96% Coulombic efficiency after 700 cycles. In addition, solvation-modulated Na promotes the excellent structural stability of zinc hexacyanoferrate (ZnHCF) due to the rhombohedral-rhombohedral rather than rhombohedral-cubic phase transition. A ZnHCF//Zn full cell delivers an average voltage of 1.76 V and 98% capacity retention after 2000 cycles at 5 C rates.
水系钠锌混合离子电池因其高能量密度、低成本和环境友好性而受到广泛关注。不幸的是，它们仍存在一些缺点，如低电压和循环性能退化，这限制了其实际应用。在此，报道了一种具有溶剂化调节锌的浓水系电解质，它减少了锌金属表面的析氢反应，避免了氧化锌的生成和不均匀沉积。因此，锌阳极在700次循环后表现出1600小时的锌电镀/剥离和≈99.96%的库仑效率。此外，由于菱面体-菱面体而非菱面体-立方相转变，溶剂化调节的钠促进了六氰合铁酸锌（ZnHCF）优异的结构稳定性。一个ZnHCF//Zn全电池在5C倍率下2000次循环后平均电压为1.76V，容量保持率为98%。
